Rate of arctic summer sea ice loss is 50% higher than predicted

Source: The Guardian

Sea ice in the Arctic is disappearing at a far greater rate than previously expected, according to data from the first purpose-built satellite launched to study the thickness of the Earth's polar caps.

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This rate of loss is 50% higher than most scenarios outlined by polar scientists and suggests that global warming, triggered by rising greenhouse gas emissions, is beginning to have a major impact on the region. In a few years the Arctic ocean could be free of ice in summer, triggering a rush to exploit its fish stocks, oil, minerals and sea routes.

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"Preliminary analysis of our data indicates that the rate of loss of sea ice volume in summer in the Arctic may be far larger than we had previously suspected," said Dr Seymour Laxon, of the Centre for Polar Observation and Modelling at University College London (UCL), where CryoSat-2 data is being analysed. "Very soon we may experience the iconic moment when, one day in the summer, we look at satellite images and see no sea ice coverage in the Arctic, just open water."

The consequences of losing the Arctic's ice coverage, even for only part of the year, could be profound. Without the cap's white brilliance to reflect sunlight back into space, the region will heat up even more than at present. As a result, ocean temperatures will rise and methane deposits on the ocean floor could melt, evaporate and bubble into the atmosphere. Scientists have recently reported evidence that methane plumes are now appearing in many areas. Methane is a particularly powerful greenhouse gas and rising levels of it in the atmosphere are only likely to accelerate global warming. And with the disappearance of sea ice around the shores of Greenland, its glaciers could melt faster and raise sea levels even more rapidly than at present.

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"The Arctic is particularly vulnerable to the impact of global warming," said Rapley. "Temperatures there are rising far faster than they are at the equator. Hence the shrinking of sea-ice coverage we have observed. It is telling us that something highly significant is happening to Earth. The weather systems of the planet are interconnected so what happens in the high latitudes affects us all."

3. It is scary! n/t

21. Its interesting that the info....

Is being revealed in 2012, but I always had a feeling it would. Its like the drip drip of flood gates. Things are happening that had predicted by some scientists though previously denied by others. Now all of this climate change info is coming out and scientists are acting like they're surprised. I'm not.

2. As you said in another thread, we're into a Cat. 5 Climate Emergency

I think that's a very reasonable way of looking at what's happening now.

It seems that the tipping point into irreversible and rapidly deteriorating climate change has arrived. A bit ahead of schedule, but never mind.

The question on the table is, "Now what?" It's not going to be a short-term emergency, this probably marks a permanent shift to a new, much less benign climate regime. It's going to impact the Northern Hemisphere's food and water supplies quite hard, starting now and continuing on into the foreseeable future. It seems to me that we're going to have to undertake extremely rapid and severe adaptation measures.

14. Oh, I have no doubt it will be done.

We'll try every last blessed thing we can think of once things have gotten too bad to tolerate. In the end we will eat the songbirds out of the trees if we have to.

I've given up on "environmentalists" at this point too. Most of the movement still believes in trying to preserve some kind of global growth - in numbers, activity, economies - when all of that that is demonstrably the problem. The cultural programming is too deeply set in all of us to permit any mass turnaround of our behaviour within the next 10 years - which is when it has to happen if we're to avoid the very worst sorts of global immiseration.

16. There is no single right or wrong....

I see people who learn to live with tiny carbon footprints as part of the long term answer.

I've been riding my bike to work (when possible) and for errands all my adult life. I see more and more kids (I call 20 somethings kids) doing the same. Life examples are more powerful than we think.

But people who fight to make sure aluminum oxides aren't used are also part of the solution. The saddest thought out there is this: It's looking more and more like no intervention = on the road to Venus. We may have fucked up that bad for that long.

17. I agree.

Unfortunately it's equally possible that even intervention = on the road to Venus. Yes, we have well and truly made an enormous miscalculation. It's really too bad - this was a pretty nice place, once upon a time.

Some people take comfort from the fact that there have been times in the history of the planet when greenhouse gas concentrations were much higher than now. The world was very different, but there was no runaway greenhouse and life endured. James Hansen devotes the entire tenth chapter of Storms of My Grandchildren to considering whether this assessment is valid. Three things give him pause:

1.The sun is brighter now than it was during past periods with very high greenhouse gas concentrations. The 2% additional brightness corresponds to a forcing of about 4 watts per square metre and is akin to a doubling of CO2 concentrations.
2.For various reasons, the greenhouse gas concentrations in past hot periods may not have been as high as we thought.
3.We are introducing greenhouse gases into the atmosphere far more quickly than natural processes ever did. This might cause fast (positive) feedback effects to manifest themselves forcefully, before slower (negative) feedback effects can get going.

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The paleoclimate record does not provide a case with a climate forcing of the magnitude and speed that will occur if fossil fuels are all burned. Models are nowhere near the stage at which they can predict reliably when major ice sheet disintegration will begin. Nor can we say how close we are to methane hydrate instability. But these are questions of when, not if. If we burn all the fossil fuels, the ice sheets almost surely will melt entirely, with the final sea level rise about 75 meters (250 feet), with most of that possibly occurring within a time scale of centuries. Methane hydrates are likely to be more extensive and vulnerable now than they were in the early Cenozoic. It is difficult to imagine how the methane clathrates could survive, once the ocean has had time to warm. In that event a PETM-like warming could be added on top of the fossil fuel warming.

After the ice is gone, would Earth proceed to the Venus syndrome, a runaway greenhouse effect that would destroy all life on the planet, perhaps permanently? While that is difficult to say based on present information, Iíve come to conclude that if we burn all reserves of oil, gas, and coal, there is a substantial chance we will initiate the runaway greenhouse. If we also burn the tar sands and tar shale, I believe the Venus syndrome is a dead certainty.

Researchers from the University of New South Wales in Australia and Purdue University in the US said global warming will not stop after 2100, the point where most previous projections have ended.

In fact temperatures may rise by up to 12C (21.6F) within just three centuries making many countries into deserts. The study, published in the prestigious journal Proceedings of the National Academy of Sciences, said humans will not be able to adapt or survive in such conditions.

Professor Tony McMichael, one of the authors, said if the world continues to pump out greenhouse gases at the current rate it will cause catastrophic warming.

"Under realistic scenarios out to 2300, we may be faced with temperature increases of 12 degrees or even more," he said. "If this happens, our current worries about sea level rise, occasional heatwaves and bushfires, biodiversity loss and agricultural difficulties will pale into insignificance beside a major threat - as much as half the currently inhabited globe may simply become too hot for people to live there."

42. Good point indeed.

10*C is far from anything to scoff at, of course.

One of the few hopes we may have is if the Chinese expansion bubble bursts sooner rather than later. While prospects such as a civil war, and/or a major famine, in which tens of millions are killed or starve to death are indeed highly unfortunate it would be nowhere near as bad as 500 million starving, AND the major contributions to continued warming.

As bad as a near future burst would be for China, one good thing would come out of that; one of the world's largest polluters will have been taken out of the picture for a while. Think of a volcanic eruption, and how new plants often begin to grow where the old ones died; when the old Chinese industrie & government wither away and die, then let us hope than a shiny, new, democratic GREEN state is born from the ruins, like the mythological Phoenix.

38. It seems to me that the time has come to live a life of awe and respect

It is long overdue.

From here, no matter what happens, our plans won't change. We will try and teach our children to treat others like they would like to be treated. We will try (understanding the increasing difficulty of this task as the world around us is altered) to grow and raise and create as much of our own resources as possible. We will try to tread as lightly as possible. We will continue to learn ways to live contentedly with less. We will try to remember to love and laugh. We will try to remember to look at the magnificence around us, to watch, listen and learn from it.

I have come a long way in learning to accept our future, whatever it may be. Unfortunately, I still have a long way to go...

28. I think history will see us all as optimists...

... at best.

I don't think we can accurately define the problem yet because we have not yet identified and described all of the variables. But it is already clear that there is more than one exponentially increasing variable in the problem for which we have yet to account.

That, I think, is why the problem now grows faster than we can accurately predict. We have created a disaster larger than we can imagine.

43. The fact is, not necessarily.

The jury's still out on this, and there ARE solutions that can help fix this problem.

If things truly go down the shitter, it is far more than likely that history may not even see certain factions amongst us as optimists, but rather, if anything at all, extreme pessimists who didn't understand the full reality behind climate change(i.e. thinking that humanity would go extinct or that Earth would turn into Venus, even if not literally so), and ultimately unwittingly helped along our civilization's demise and ruin....perhaps not nearly as much as the deniers and their idols, though, but still somewhat responsible themselves

Honestly, if this kind of thinking had been prevalent during the American Revolution, we'd have lost everything we'd ever worked for and we'd be a British satellite today. And yes, it's that important to me, and most of the rest of us.

33. I am really confused about this from a scientific point of view.

As I understood it. There is a massive swirling current up there in the northern lattitudes holding that increased volume of water to the north. So we have not see the abrupt 1-2 inch sea rise scientists have been warming about...

You see my question is...

When is the volume tipping point going to happen and this massive amount of water will quite literally flush the Atlantic ocean causing a great coastal tidal surge?